I vaguely remember using a Firefox extension a long time ago that allowed one to whitelist / sticky a handful of domains that would be spared from the usual "delete every cookie", giving the user a renewed sense of control over what the web knows about them.

Nowadays with online fingerprinting¹ this may amount to nothing more than placebo, but I do miss it.

Called self-destructing cookies. It broke with web extensions and cannot be replaced (like many other add-ons I use) because the web extension APIs to provide the functionality do not exist. I'm still on Firefox 55 though, so I can still use it (like firegestures, quickjava, no close buttons, vertical tabs, and others that are labeled as legacy).

I always find it very creepy when I looked something up on someone else's laptop and use it again half a year later, only to find that it remembers my last visit and (for example) centers the map where I last left it. I'm so used to having things be cleaned up against tracking, I don't even really experience what the web is like these days.